Carburetor



June 19, 192s. 1,674,029

GfR. WELCH GARBURETOR Filed Feb. 16, 1924 APatented June 19, 1928.

UNITED STATES PATENT orifice.

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CABBUBETOB.

appunti mea February 1e, 1924. semi ne. 693,199.

The object of this invention is to provide means whereby the accelerating charge of an automobile carburetor will not be depleted by the low speed operationfof the carbu- 5 retor.

In Figure 1 the principle of operation is illustrated by a cross sectional elevation of a carburetor.

Figure 2 is a cross Sectional elevation l' through a modified carburetor incrporating the invention. This figures is taken on the plane 2-2 of Figure 3.

Fi re 3 is a cross sectional elevation on the p ane 3-3 of Figure 2.

Figure 4 is a partial sectional plan view taken on the plane 4--4 of Figure 2.

In Figure 1, a is the air entrance, .b is the Venturi tube, c is the mixture outlet, d is the throttle located therein, e is the fuel nozzle l controlled by a needle valve f and located in `a. well h. g is'the primary air passage leading to the`well h, which discharges into the throat of the Venturi tube b. A' passage y' connects the well h, opposite the discharge point of the nozzle e, to the mixture outlet c adjacent to the lip of the throttle valve d so that the passage j is progressively subjected to the depression existing in c as the throttle valve 1sopened in the direction a0 shown lby the arrows.

Connecting the primary air passage g and the well h the level at the upper endof the nozzle e, A and therefore is substantially at thesame level at which the low speed fuel assage j communicates with the well h. A he passagek for convenience may b e connected to j the passage g, as shown, or it may alternatively be inde ndent of the passage g, thus 40 forming an'a togsther se arate air passage for venting the el nozz e e.

In Figures 2, 3, and 4, the capital letters A,B, C, D, E, F, G, H, J, and K refer to parts having the same functions as the corresponding parts in Figure 1.A In` addition the oat mechanism vis show n consisting of thellloat L hinged at M and operating the needle valve N. This oat maintains the fuel on the level X-Y of Figures 2 and 3,

ao this level being substantially the level of the auxiliary air passage K.

1s another passage la located at- Normal operation- When running slowly air is drawn through the auxiliary air passage k, past the fuel nozzle e, and so into the passage j, whence the mixture of fuel and air is discharged adjacent to Aand in advance of the throttle d, as shown in Figure 1. The area of K (Fig. 2) is made consid. erably larger than the passage J, so that'the resistance to flow through K when the enel. glue is running slowly (that is on the fuel flow through is so small that fuel will accumulate in the bottom of G. On opening` the throttle wide the depression in the Venturi tube b increases and fuel is discharged from e through h directly into the Venturi tube Z.

Acceleration-Thereupon the fuel held in reserve in `g is displaced by the atmospheric pressure acting upon it, the fuel moves down Ag and up past the nozzle'e, thereby emptying the well h and passage g, and thus providing the accelerating charge so necessary n order to get smooth operation, especially with a cold motor. The'operation during acceleration of the device shown in Figures 2, 3, and 4 is substantially identical with the operation of Figure 1.

What I claim is:

In a carburetor having a main mixing chamber of Venturi form', a mixture outlet, a throttle valve therein, a well distinct from and communicating with said mixing chamber, a fuel nozzle discharging therein and extending above the bottom vof said well, a low speed fuel'passage communicating with the well at, a point adjacent to the point ofdischarge of the said fuel nozzle and communicating with the mixture outletadjacent to and in advance of said throttle valve, a. pri-f mary air passage leading from the atmosphere to the bottom of said well, an additional primary air assa communicating with the well at a polnt adjacent to the point at which the fuel nozzle dischargesin saidA well, whereby the fuel contained in the well is vheld in reserve during slow speed ojeration for use during the subsequent acce erations' V a In testimony whereof I allx my signature.

esonera. WELCH. 

